High power LED housing and fabrication method thereof

ABSTRACT

An LED housing, in which a heat conducting part has a chip mounting area, a heat connecting area opposed to the chip mounting area and a neck between them. Fixing parts have first ends engaged with the neck. An electrical connecting part has a wire connecting area placed adjacent to the chip mounting area and an external power connecting area connected to the wire connecting area. A housing body of molding material integrally holds the heat conducting part, the fixing parts and the electrical connecting part while isolating the electrical connecting part from the heat conducting part. The LED housing fixes the neck of the heat conducting part at both sides, thereby stably coupling the heat conducting part to the housing body. The fixing parts can spread heat from the heat conducting part to lateral regions of the LED housing, thereby more efficiently spreading heat.

CLAIM OF PRIORITY

This application claims the benefit of Korean Patent Application No.2005-13249 filed on Feb. 17, 2005, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an LED housing and a fabrication methodthereof. More particularly, the LED housing of the present invention cansecurely fix a neck of a heat conducting part at both sides with a pairof fixing parts, thereby stably coupling the heat conducting part to ahousing body made of resin, while allowing the fixing parts to spreadheat from the heat conducting part to lateral regions of the LEDhousing, thereby more efficiently spreading heat within the LED housing.

2. Description of the Related Art

A Light Emitting Diode (LED) is a semiconductor device that is activatedin response to electric current to generate various colors of light. Thecolor of light generated by the LED is mainly determined by chemicalcomponents of LED semiconductor. Such LEDs have several merits such aslonger lifetime, lower driving voltage, better initial activationcharacteristics, higher vibration resistance and higher tolerance onrepetitive power switching over conventional lighting devices usingfilaments, and thus demand for them is gradually on the rise.

In particular, some LEDs such as high power LEDs are recently adopted inillumination systems and backlight units for large-sized Liquid CrystalDisplays (LCDs). Such high power LEDs are required to have superiorthermal radiation performance because these systems or units requirelarger power.

FIG. 1 illustrates a typical high power LED package, in which FIG. 1(a)is a perspective cross-sectional view of the high power LED, and FIG.1(b) is a cross-sectional view of the high power LED mounted on acircuit board.

Referring to FIG. 1(a) first, an LED package 10 includes a thermalconnecting member 14 (so-called heat slug) with an LED chip 12 seatedthereon. The thermal connecting member 14 also functions as heat guidemeans. The LED chip 12 is powered from an external power source (notshown) via a pair of wires 16 and a pair of leads 18. An encapsulant 20encapsulates the top portion of the thermal connecting member 14including the LED chip 12, and a lens 22 is capped on the encapsulant20. A housing 24 is formed typically by molding, surrounding the thermalconnecting member 14 to support the thermal connecting member 14 and theleads 18.

The LED package 10 shown in FIG. 1(a) is mounted on a mother board 30 asa heat sink as shown in FIG. 1(b) to constitute an LED assembly 40. Aheat conductive pad 36 such as solder is interposed between the heatconducting member 14 of the LED package 10 and a metal body 32 of themain board 30 to promote heat conduction between them. In addition, theleads 18 are also stably connected to a circuit pattern 34 of the mainboard 30.

The LED package 10 and its mounting structure on the main board 30 asshown in FIG. 1 are focused to thermal radiation to efficiently radiateheat to the outside. That is, the LED package 10 is so designed that thethermal connecting member 14 as a heat sink is mounted directly or viathe thermal conductive pad 36 on the main board 30 in order to radiateheat absorbed from the LED chip 12 to the outside. Then, a majorquantity of heat from the LED chip 12 is conducted through the thermalconnecting member 14 to the main board 30 and only a minor quantity ofheat is radiated to the air through the surface of the LED package 12including the housing 24 and the lens 22.

However, this structure is disadvantageously complicated to obstruct theautomation of LED package fabrication as well as require a large numberof components to be assembled together, thereby burdening manufacturecost.

FIG. 2 illustrates a leadframe structure of a high power LED packagedisclosed by US Patent Application Publication No. 2004/0075100.Referring to FIG. 2, a leadframe 2 and a thermal conducting part 4 areshown. The leadframe 2 is subdivided into two electrical connectingparts 12 a and 12 b, which end in a respective solder connecting strip 3a, 3 b.

One electrical connecting part 12 a has an opening in the form of aneye. The thermal connecting part 4 is linked into the eye opening. Thethermal connecting part 4 is substantially rotationally symmetrical andhas projections 19 that allow the leadframe 2 to be anchored in a robustmanner in a housing. Furthermore, the thermal connecting part 4 has acentral recess in the form of a reflector well 16, on whose base surfacea chip-mounting area 11 is provided for holding a radiation-emittingchip. The side surfaces of the recess are used as reflector surfaces.

The eye ring of the electrical connecting part 12 a has a cutout 13, atwhich a bonding wire connecting area 10, which is in the form of atongue, of the second electrical connecting part 12 b overlaps. Thebonding wire connecting area 10 is disposed at a different height tothat edge of the reflector well 16 that emits radiation. For chipmounting purposes, the configuration allows short wire connectionsbetween the chip and the bonding wire connecting area 10 without anyneed for a cutout for this purpose at the edge of the reflector well 16in the thermal connecting part.

Herein the reference sign 27 designates the main radiation emissiondirection 27 of the component.

Such a leadframe structure can be fabricated in more simple process overthe package structure illustrated in FIG. 1 since the package body canbe molded from resin with the first electrical connecting part 12 ainserted into the thermal connecting part 4.

However, this structure can be restrictively used for a structure wherethe electrical connecting part 12 a is electrically connected to thethermal connecting part 4 since the electrical connecting part 12 adirectly contacts the thermal conductive part 4. This cannot be used fora structure requiring the electrical connecting part 12 a insulated fromthe thermal connecting part 4.

Furthermore, this document does not teach any fabrication method of apackage structure that can be used in such an insulated structure.

SUMMARY OF THE INVENTION

The present invention has been made to solve the foregoing problems ofthe prior art and it is therefore an object of the present invention toprovide an LED housing which can securely fix a neck of a heatconducting part at both sides with a pair of fixing parts, therebystably coupling the heat conducting part to a housing body made ofresin, and allow the fixing parts to spread heat from the heatconducting part to lateral regions of the LED housing, thereby moreefficiently spreading heat within the LED housing.

It is another object of the invention to provide a fabrication method ofan LED housing which can fabricate an LED housing easily and stably bycarrying out resin molding with a heat conducting part inserted into apair of fixing parts of a frame to form a housing body, taking aresultant structure out of a mold when resin is cured, and separatingthe LED housing from the frame. This object is also aimed to use theframe with the fixing parts and an electrical connecting part formedtherein as means for fixing the heat conducting part in order toautomate fabrication, thereby saving cost and improving productivity.

In order to realize the foregoing objects, the invention provides an LEDhousing comprising: a heat conducting part having a chip mounting areafor mounting a LED chip, a heat connecting area opposed to the chipmounting area and a neck formed between the chip mounting area and theheat connecting area; a pair of fixing parts each having a first endengaged with the neck of the heat conducting part to fix the heatconducting part; an electrical connecting part having a wire connectingarea placed adjacent to the chip mounting area of the heat conductingpart and an external power connecting area connected to the wireconnecting area; and a housing body of molding material integrallyholding the heat conducting part, the fixing parts and the electricalconnecting part while isolating the electrical connecting part from theheat conducting part.

Preferably, the first end of the fixing parts is adapted to hold aroundthe neck.

Preferably, the fixing parts may have a hole for receiving a portion ofthe housing body.

Preferably, each of the fixing parts may have a second end extended to aside surface of the housing body to spread heat from the heat conductingpart in lateral direction of the housing body, and the housing body mayhave a caved-in side portion so that the second ends of the fixing partsare projected out of the housing body.

Preferably, the housing body may have a cavity Configured to expose thechip mounting area of the heat conducting part and the wire connectingarea of the electrical connecting part. In this case, the housing bodymay have a step connected around the chip mounting area of the heatconductive area within the recess.

Furthermore, the housing body may have a groove connected around theheat connecting area of the heat conducting part.

In order to realize the foregoing objects, the invention also provides afabrication method of a LED housing, comprising steps of:

(a) preparing a heat conducting part having a chip mounting area, a heatconnecting area opposed to the chip mounting area and a neck formedbetween the chip mounting area and the heat connecting area;

(b) machining a sheet metal to prepare a frame having a circumferencepart, a pair of fixing parts and at least one electrical connecting parteach having a first end extended from the circumference part toward thecenter of the frame, and a hole formed in the circumference part;

(c) assembling the heat conducting part to the frame to produce a heatconducting part-frame assembly, wherein the first ends of the fixingparts engage with the neck of the heat conducting part and a first endof the electrical connecting part is placed adjacent to the chipmounting area;

(d) mounting the heat conducting part-frame assembly in a mold;

(e) injecting molding material into the mold to form a housing body thatintegrally holds the heat conducting part, the fixing parts and theelectrical connecting part while isolating the electrical connectingpart from the heat conducting part; and

(f) cutting the fixing parts and the electrical connecting part from theframe.

In order to realize the foregoing objects, the invention also provides afabrication method of a LED housing, comprising steps of:

(a) preparing a plurality of heat conducting parts each having a chipmounting area, a heat connecting area opposed to the chip mounting areaand a neck formed between the chip mounting area and the heat connectingarea;

(b) machining a sheet metal into a frame array sheet having acircumference area with holes and a plurality of frame areas surroundedby the circumference area, wherein each of the frame areas has acircumference part and a pair of fixing parts, and at least oneelectrical connecting part each having a first end extended from thecircumference part toward the center of the frame;

(c) assembling the heat conducting parts to the frame array sheet toproduce a plurality of heat conducting part-frame assemblies, whereinthe first ends of the fixing parts engage with the neck of the heatconducting part and a first end of the electrical connecting part isplaced adjacent to the chip mounting area;

(d) mounting the heat conducting part-frame assemblies in molds;

(e) injecting molding material into the molds to form a plurality ofhousing body each of which integrally holds the heat conducting part,the fixing parts and the electrical connecting part while isolating theelectrical connecting part from the heat conducting part; and

(f) cutting the fixing parts and the electrical connecting part from theframe area sheet.

Preferably, the sheet metal machining step (b) may comprise punching thesheet metal.

Preferably, the heat conducting part assembling step (c) may comprisepushing the heat conducting part with the chip mounting area firstbetween the opposed first ends of the fixing parts so that the firstends hold the neck of the heat conducting part.

Preferably, the heat conducting part-frame assembly mounting step (d)may comprise inserting a guide pin of the mold into the hole of theframe or frame array sheet to guide the mold.

Preferably, the molding material injecting step (e) is so carried out toexpose the chip mounting area of the heat conducting part and the firstend of the electrical connecting part.

The fabrication method of the invention may further comprise a step of:(g) curing the molding material and taking out a cured resultantstructure before or after the cutting step (f)

Furthermore, the fabrication method of the invention may furthercomprise a step of: bending a portion of the electrical connecting partthat is extended to the outside after the resultant structure taking outstep (g).

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a sectional view of a general high power LED package and amounting structure thereof;

FIG. 2 is a top and side elevational view of a conventional leadframestructure of a high power LED package;

FIG. 3 is a perspective view of an embodiment of a high power LEDhousing according to the invention;

FIG. 4 is a plan view of the LED housing shown in FIG. 3;

FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 4;

FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 4;

FIG. 7 is a bottom perspective view of the LED housing shown in FIG. 3;

FIG. 8 is a perspective view of the LED housing shown in FIG. 3, mountedwith an LED chip thereon;

FIG. 9 is a cross-sectional view of a high power LED package of theinvention having an LED housing as shown in FIG. 3;

FIG. 10 is a cross-sectional view of another embodiment of the LEDhousing according to the invention, taken in a section corresponding toFIG. 6;

FIG. 11 is a cross-sectional view of further another embodiment of theLED housing according to the invention, taken in a section correspondingto FIG. 5;

FIG. 12 is a cross-sectional view of other embodiment of the LED housingaccording to the invention, taken in a section corresponding to FIG. 5;

FIG. 13 is a cross-sectional view of a high power LED package of theinvention having an LED housing as shown in FIG. 12;

FIG. 14 is an exploded perspective view of a fabrication process of ahigh power LED housing according to the invention, illustrating a heatconducting part and a leadframe prior in position prior to beingassembled together;

FIG. 15 is a plan view of the heat conducting part and the leadframeshown in FIG. 14, illustrating the heat conducting part assembled withthe leadframe;

FIG. 16 is a side elevational view seen in the direction of an arrowfrom the line XVI-XVI in FIG. 15;

FIG. 17 is a cross-sectional view taken along the line XVII-XVII in FIG.15;

FIG. 18 is a plan view of a housing body formed by molding resin on astructure shown in FIG. 15;

FIG. 19 is a cross-sectional view taken along the line XIX-XIX in FIG.18;

FIG. 20 is a cross-sectional view taken along the line XX-XX in FIG. 18;

FIG. 21 is an exploded perspective view of another fabrication processof a high power LED housing according to the invention, illustrating aframe sheet having a number of leadframe areas corresponding to theleadframe shown in FIG. 14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiment of the present invention will now be described indetail with reference to the accompanying drawings.

Referring to FIGS. 3 to 7 first, an LED housing 100 of the inventionincludes a heat conducting part 110, a pair of fixing parts 120, a pairof electric connecting parts 120 and a housing body 150.

The heat conducting part 110 is made of a lump of metal preferablyhaving high heat conductivity. The heat conducting part 110 has a chipmounting area 112 on which an LED chip (refer to FIG. 8) is mounted, aheat connecting area 114 opposite to the chip mounting area and a neck116 of a reduced width between the chip mounting and heat connectingareas 112 and 114.

The fixing parts 120 each have a holder 122 formed at a first end 120 athereof inside the housing 100, engaged with the neck 116 of the heatconducting part 110. The holders 122 are curved inward with a curvaturethe same as that of the neck 116 as shown in FIG. 14 to hold the neck116 at both sides, thereby fixing the heat conducting part 110.Furthermore, the fixing part 120 is led from the first end 120 a to asecond end 120 b to spread heat from the heat conducting part 110 inlateral direction. Therefore, it is preferable that the fixing part 120is made of high heat conductivity metal.

The second end of the fixing part 120 is exposed to the outside througha side recess 158 formed in a lateral portion of the housing body 150.The fixing part 120 has a hole 124 formed between the first end 120 aand the second end 120 b to receive a disk-like fixing area 154 of thehousing body 150. As a result, the fixing part 120 is more tightly fixedto the housing body 150 thereby more securely fixing the heat conductingpart 110.

As stated above, since the holder 122 at the first end 120 a of thefixing part 120 is engaged with the neck 116 of the heat conducting part110 and the hole 124 of the fixing part 120 is engaged with the fixingarea 154 to securely fix the fixing part 120 to the housing body 150,the fixing part 120 securely fixes the heat conducting part 110. At thesame time, the second end of the fixing part 120 is extended to the sidesurface of the housing body 150 thereby spreading heat from the heatconducting part 110 in lateral direction.

The heat conducting part 130 is made of a strip-shaped lead forelectrical connection, and has a wire connecting area formed at a firstend 130 a thereof placed adjacent to the chip mounting area 112 of theheat conducting part 110 and an external power connecting area formed atthe second end 130 b extended outside the housing body 150. Indentations132 are formed in portions of the electrical connecting part 130adjacent to the first end 120 a to house rectangular fixing portions 156of the housing body 150. This makes the electrical connecting part 130be securely coupled with the housing body 150.

The housing body 150 is integrally formed from molding compound so thatit has a substantially flat box-like configuration. The housing body 150integrally holds the heat conducting part 110, the fixing parts 120 andthe electrical connecting parts 130 while isolating the heat conductingpart 110 from the electrical connecting part 130.

In a central area of the upper part 150 a of the housing body 150, thereis provided a circular cavity C that is configured to expose the chipmounting area 112 of the heat conducting part 110, the fixing parts 120in part adjacent to the first end 120 a and the first end 130 a of theelectrical connecting part 130. The fixing portions 154 and 156 of thehousing body 150 are also exposed upward through the cavity C.

The side recesses 158 are also formed in the side portions of thehousing body 150 to expose the second ends of the fixing parts 120. Inthe lower part 150 b of the housing body 150, an annular groove 160 isformed to expose the heat connecting area 114 of the heat conductingpart 110.

FIG. 8 is a perspective view of the LED housing 100 mounted with an LEDchip 102 thereon. Referring to FIG. 8, the LED chip 102 is mounted onthe chip mounting area 112 of the heat conducting part 110 by forexample adhesive, and connected to the first ends 130 a of theelectrical connecting parts 130 by wires 104. The electrical connectingpart 130 is connected by the second ends 130 b to an external powersource (not shown) so that the LED chip 102 is supplied with power viathe electrical connecting parts 130 and the wires 104.

FIG. 9 is a cross-sectional view of a high power LED package of theinvention embodied by capping a transparent cover 170 on an LED housing100 of the invention. The LED package of the invention shown in FIG. 9includes the LED housing 100 the same as shown in FIG. 3, a cover 170capped on the top of the LED housing 100 and a transparent encapsulant180 filled into a cavity of the cover 170.

The cover 170 is a transparent lens made by injection molding of forexample transparent plastic, and shaped symmetrically about the axis A.The cover 170 has a reflecting surface 172 for reflecting lightgenerated from the LED chip 102, an upper radiating surface 174 forradiating reflection light to the outside and a lower radiating surface176 extended downward from the upper radiating surface 174 to radiatelight directly incident thereon from the LED chip 102 to the outside.

The transparent encapsulant provided between the cover 170 and the LEDhousing 100 is preferably made of elastic resin. The elastic resin mayinclude gel type substance such as silicone which has not only excellentoptical characteristic due to large refractive index but also excellentresistance against yellowing, that is, change in quality caused bysingle wavelength light. Furthermore, silicone maintains jell orelastomer state even after hardening, and thus can stably protect theLED chip 102 from stress, vibrations and external impact.

Of course, the shape of the cover 170 is illustrative only, but varioustypes of lenses and covers can be used instead. For example, thedome-shaped lens 22 as shown in FIG. 1 can be used. Furthermore, thetransparent encapsulant 180 made of elastic material can be optionallyomitted or substituted with other material.

FIG. 10 illustrates another embodiment of the LED housing according tothe invention. Describing the LED housing 100-1 of this embodiment, anLED chip 102 is electrically connected to an electrical connecting part130 by a wire 104 and to a heat conducting part 110 by a wire 106. Inthis fashion, the heat conducting part 110 itself functions as aterminal. Then, another heat conducting part 130 shown in dotted linecan be omitted or cut along trimming line Lc. Alternatively, it ispossible to use the heat conducting part 110 as one terminal but both ofthe electrical connecting parts 130 as the other terminal. Otherconstruction of the LED housing 100-1 of this embodiment issubstantially the same as that of the LED housing 100 of the firstembodiment. The same or similar components are designated with the samereference signs and their description will be omitted.

FIG. 11 illustrates further another embodiment of the LED housingaccording to the invention. Describing the LED housing 200 of thisembodiment, in a heat conducting part 210, a chip mounting area 212 isprotruded at the outer circumference upward to surround an LED chip 202,thereby forming a reflector 218. The inside of the reflector 218 isshaped as a concave mirror in order to reflect light generated by theLED chip 202 in upward direction. Other construction of the LED housing100-1 of this embodiment is substantially the same as that of theabove-described LED housing 100. The same or similar components aredesignated with the same reference signs by the 200s, and theirdescription will be omitted.

FIG. 12 illustrates other embodiment of the LED housing according to theinvention. Describing the LED housing 300 of this embodiment, a housingbody 300 is extended by its outer circumference beyond a chip mountingarea 312 of a heat conducting part 310 and an LED chip 302 to form acavity C around them. The housing body 300 has an inside slope formedaround the cavity C and a curved outside surface.

optionally, the housing body 300 may be made of high reflectivitypolymer. In this fashion, it is possible to reflect light generated bythe LED chip 302 in upward direction by using the slope 362 as areflecting surface.

For a polymer of a high reflectivity, NM114WA and NM04WA, which areproduct names of Otsuka Chemical Co., Ltd. can be used. Specifically,NM114WA has an initial reflectivity of 88.3% and maintains areflectivity of 78.0% after two hours for a wavelength of 470 nm. NM04WAhas an initial reflectivity of 89.0% and maintains a reflectivity of89.0% after two hours for a wavelength of 470 nm. For an excellentreflectivity molding material, those containing TiO2 are known in theart.

Alternatively, the housing body 300 can be made of metal or polymer of alow reflectivity and high reflectivity material can be provided in theform of a film on the slope 362. This film can be realized using metalof a high reflectivity or the above-described polymer of a highreflectivity.

FIG. 13 illustrates a high power LED package of the invention embodiedby capping a transparent cover 370 on an LED housing 300 as shown inFIG. 12.

More specifically, a transparent encapsulant 380 is formed in a cavity Cof the LED housing 300, and a transparent cover 370 is bonded to the topof the housing 300. The transparent 380 may be made of for example epoxyresin, and preferably, elastic resin as described above.

The transparent cover 370 is provided with a reflecting surface 372 anda radiating surface 374 for radiating reflected light to the outside.The cover 370 is shaped symmetrically about the axis A or rotationallysymmetric.

The housing body 300 may also be made of transparent resin. A roundedsurface 364 of the housing body 300 functions as a lower radiatingsurface that radiates light generated from an LED chip 302 in lateraldirection. In this fashion, the light radiation pattern produced by thewhole LED package is substantially the same as that produced by the LEDpackage of FIG. 9.

A fabrication process of the LED housing 100 of the invention asdescribed above with reference to FIGS. 3 to 7 will now be describedwith reference to FIGS. 14 to 20.

(1) Preparing Heat Conducting Part and Frame

First, as shown in FIG. 14, a heat conducting part 110 and a frame 140are prepared.

The heat conducting part 110 is prepared preferably by cutting a metallump or metal rod. The prepared heat conducting part 110 is configuredthe same as the heat conducting part 110 of the LED housing 100 asillustrated in FIGS. 3 to 7.

The frame 140 is produced from a sheet metal or metal plate preferablyby punching. The produced frame 140 is rectangular, and has acircumference part 142, a pair of fixing parts 120 and a pair ofelectrical connecting parts 130, in which the fixing parts 120 and theelectrical connecting parts 130 are shaped as a lead extended from thecircumference part 142 toward the center. Other areas of the frame 140excluding the fixing parts 120, the electrical connecting parts 130 andthe outer circumference 142 are opened, and guide holes 144 areperforated in for corners of the outer circumference part 142.

The guide holes 144 are adapted to locate the frame 140 whilemaintaining its position. For example, the guide holes 144 serve toreceive guide pins of a mold (not shown) when the frame 140 is mountedto the mold in following process.

Each of the fixing parts 120 has a first end 120 a with a holder 122 forengaging with the neck 116 of the heat conducting part 110 and thesecond end 120 b led to the outer circumference 142 of the frame 140.The holders 122 are formed with a curvature preferably the same as thatof the neck 116 of the heat conducting part 110. Preferably, the firstends 120 a of the fixing parts 120 are spaced to a suitable distance sothat the holders 122 form a circle matching the neck 116 when connectedwith arcs of equal curvature. If the neck 116 is angled, the holder 122will be angled with a corresponding configuration.

(2) Assembling Heat Conducting Part to Frame

The heat conducting part 110 is pushed upward from the position shown inFIG. 14 to be mounted or assembled to the frame 140. The heat conductingpart 110 shoves out the fixing parts 120 of the frame 140 as it is movedupward, such that the fixing parts 120 are bent upward and then restoreto the original position by the elasticity. Then, the holders 122 of thefixing parts 120 hold the neck 116 at both sides so that the heatconducting part 110 is mounted or assembled to the frame 140. Theengagement of the holders 122 with the neck 116 is as shown in FIGS. 15and 16.

The first ends 130 a of the electrical connecting parts 130 are arrangedadjacent to the heat conducting part 110 as shown in FIG. 17. Althoughthe electrical connecting parts 130 are arranged adjacent to the neck116 and the chip mounting area 112 of the heat conducting part 110, theydo not contact the heat conducting part 110 but maintain a distancetherefrom.

In this manner, the holders 122 of the fixing parts 120 engage aroundthe neck 116 to fix the heat conducting part 110 to the frame 140 sothat the heat conducting part 110 can maintain its position duringfollowing process of mold-mounting and resin injection.

(3) Mold Mounting and Resin Injection

Then, the frame 140 assembled with the heat conducting part 110 ismounted to a mold (not shown) by inserting guide pins of mold into thehole 144 of the frame 140. Next, resin material or encapsulatingmaterial is injected into the mold to encapsulate the heat conductivematerial 110 and frame 140 parts adjacent to the heat conductivematerial 110, thereby molding a housing body 150 as shown in FIGS. 18 to20.

Describing in more detail, the housing body 150 is formed by molding tointegrally encapsulate a portion of the fixing part 120 adjacent to thefirst ends 120 a thereof and the heat conducting part 110, in which theheat conducting part 110 is encapsulated by the housing body 150 exceptfor the chip mounting area 112 and the heat connecting area 114.

As shown in FIG. 19, the fixing parts 120 are encapsulated by thehousing body 150 with the holders 122 engaged with the heat conductingpart 110. The top surface of each fixing part 120 adjacent to the firstend 120 a is exposed from above by the cavity C of the housing body 150.A middle portion of the fixing part 120 between the first and secondends 120 a and 120 b is inserted between the upper and lower parts 150 aand 150 b of the housing body 150, and a portion of the fixing part 120adjacent to the second end 120 b is extended out of the housing body150. The fixing areas 154 of the housing body 124 are inserted into theholes 124 of the fixing parts 120 so that the fixing parts 120 aretightly coupled with the housing body 150 to securely fix the heatconducting part 110 to the housing body 150.

As shown in FIG. 20, the top surface of each electrical connecting part130 adjacent to the first end 130 a forming the wire mounting area isexposed from above the cavity C of the housing body 150. A middleportion of the electrical connecting part 130 between the first andsecond ends 130 a and 130 b is inserted between the upper and lower pars150 a and 150 b of the housing body 150, and a portion of the electricalconnecting part 130 adjacent to the second end 130 b is extended out ofthe housing body 150. The fixing portions 156 of the housing body 150are inserted into the indentations 132 of the electrical connectionparts 130 thereby securely coupling the electrical connecting parts 130so that the electrical connecting parts 130 do not slip out of thehousing body 150 under external force.

A resultant structure produced by resin molding as above hassubstantially the same configuration as the LED housing 100 illustratedin FIGS. 3 to 7 except that the fixing parts 120 and the electricalconnecting parts 130 are still connected to the frame 140 and theelectrical connecting parts 130 are not bent at the second ends 130.

(4) Separating from Frame

When resin is cured, the above-mentioned resultant structure is takenout of the mold, the fixing parts 120 are cut along the line L1 shown inFIG. 19, and the electrical connecting pars 130 are cut along the lineL2 shown in FIG. 20 to separate the resultant structure shown in FIGS.18 to 20 from the frame 140. Then, the electrical connecting parts 130are bent at the second ends 130 a as shown in FIG. 20, thereby producingan LED housing 100 as shown in FIG. 3 to 7. Alternatively, the step oftaking the resultant structure out of the mold can be carried out thecutting and bending.

Packaging

The LED housing 100 produced as above can be used to accomplish an LEDpackage for example as shown in FIG. 9.

First, an LED chip 102 is attached to the chip mounting area 112 by forexample adhesive and electrically connected to the electrical connectingparts 130 by wires 104 so as to produce a structure as shown in FIG. 8.

Then, the structure is coupled with for example a transparent cover 170as shown in FIG. 9. In the coupling, the cover 170 is turned upsidedown, transparent encapsulant 180 of for example silicone is filled intoa hollow space of the cover 170, and then the LED housing 100 is turnedupside down and placed on the cover 170 with the LED chip 102 facingdownward. As the transparent encapsulant 180 is cured from this state,the LED package as shown in FIG. 9 can be produced.

Process on Frame Array Sheet

FIG. 21 shows a frame array sheet 146 having a plurality of frame areas140′ arrayed therein. Each frame area 140′ is shaped substantially thesame as the afore-described frame 140.

Therefore, the frame array sheet 146 can be used to produce a number ofLED housing bodies 150 in the plurality of frame areas 140′ according tothe same process as described above, in which holes H formed in theperiphery of the frame array sheet 146 are used as guide holes orlocating holes.

After forming the LED housings 100 according to the above process, theframe array sheet 146 is cut along trimming lines L1 and L2 and thesecond ends 130 a of the electrical connecting ends 130 a are bent so asto accomplish a plurality of LED housings 100. Alternatively, the LEDhousings 100 can be taken out of the mold after the cutting and bending.

As described above, the above process allows the plurality of LEDhousings 100 to be automatically produced by using one frame array sheet146.

The afore-described process fabrication of an LED housing and an LEDpackage having the same LED housing can be applied equally tofabrication of the LED housing 100 of the first embodiment as well asthe LED housings 100-1 and 200 of the second and third embodiments.

In case of the fourth embodiment, this fabrication process is equallyapplied to fabrication of the LED housing 300, but there differs incoupling the cover 370 to the LED housing 300. In the LED housing 370 ofthe fourth embodiment, transparent encapsulant 380 is filled into thecavity C beforehand as illustrated in FIG. 13, followed by coupling thetransparent cover 370 with the top of the encapsulant 380.

As described hereinbefore, the LED housing of the invention has the pairof fixing parts securely fixing the neck of the heat conducting part atboth sides, thereby stably coupling the heat conducting part to thehousing body made of resin. Furthermore, the fixing parts also functionto spread heat from the heat conducting part to lateral regions of theLED housing, thereby more efficiently spreading heat within the LEDhousing.

Besides, the fabrication process of an LED housing of the invention caneasily and stably produce an LED housing by carrying out resin-moldingwith a heat conducting part fixedly inserted into a pair of fixing partsto form a housing body, and after curing of resin, taking the housingout of a mold. Moreover, by using a frame with the fixing parts andelectrical connecting parts formed therein as means for fixing the heatconducting part, the fabrication process can be automated in order tosave cost and improve productivity.

Although the invention has been shown and described with reference tocertain preferred embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

1. An light emitting diode housing comprising: a heat conducting parthaving a chip mounting area for mounting a light emitting diode chip, aheat connecting area opposed to the chip mounting area and a neck formedbetween the chip mounting area and the heat connecting area; a pair offixing parts each having a first end engaged with the neck of the heatconducting part to fix the heat conducting part; an electricalconnecting part having a wire connecting area placed adjacent to thechip mounting area of the heat conducting part and an external powerconnecting area connected to the wire connecting area; and a housingbody of molding material integrally holding the heat conducting part,the fixing parts and the electrical connecting part while isolating theelectrical connecting part from the heat conducting part.
 2. The lightemitting diode housing according to claim 1, wherein the first end ofthe fixing parts is adapted to hold around the neck.
 3. The lightemitting diode housing according to claim 1, wherein the fixing partshave a hole for receiving a portion of the housing body.
 4. The lightemitting diode housing according to claim 1, wherein the fixing partseach have a second end extended to a side surface of the housing body tospread heat from the heat conducting part in lateral direction of thehousing body.
 5. The light emitting diode housing according to claim 4,wherein the housing body has a caved-in side portion so that the secondends of the fixing parts are projected out of the housing body.
 6. Thelight emitting diode housing according to claim 1, wherein the housingbody has a cavity Configured to expose the chip mounting area of theheat conducting part and the wire connecting area of the electricalconnecting part.
 7. The light emitting diode housing according to claim6, wherein the housing body has a step connected around the chipmounting area of the heat conductive area within the recess.
 8. Thelight emitting diode housing according to claim 1, wherein the housingbody has a groove connected around the heat connecting area of the heatconducting part.
 9. A fabrication method of a light emitting diodehousing, comprising steps of: (a) preparing a heat conducting parthaving a chip mounting area, a heat connecting area opposed to the chipmounting area and a neck formed between the chip mounting area and theheat connecting area; (b) machining a sheet metal to prepare a framehaving a circumference part, a pair of fixing parts and at least oneelectrical connecting part each having a first end extended from thecircumference part toward the center of the frame, and a hole formed inthe circumference part; (c) assembling the heat conducting part to theframe to produce a heat conducting part-frame assembly, wherein thefirst ends of the fixing parts engage with the neck of the heatconducting part and a first end of the electrical connecting part isplaced adjacent to the chip mounting area; (d) mounting the heatconducting part-frame assembly in a mold; (e) injecting molding materialinto the mold to form a housing body that integrally holds the heatconducting part, the fixing parts and the electrical connecting partwhile isolating the electrical connecting part from the heat conductingpart; and (f) cutting the fixing parts and the electrical connectingpart from the frame.
 10. The fabrication method according to claim 9,wherein the sheet metal machining step (b) comprises punching the sheetmetal.
 11. The fabrication method according to claim 9, wherein the heatconducting part assembling step (c) comprises pushing the heatconducting part with the chip mounting area first between the opposedfirst ends of the fixing parts so that the first ends hold the neck ofthe heat conducting part.
 12. The fabrication method according to claim9, wherein the heat conducting part-frame assembly mounting step (d)comprises inserting a guide pin of the mold into the hole of the frameto guide the mold.
 13. The fabrication method according to claim 9,wherein the molding material injecting step (e) is so carried out toexpose the chip mounting area of the heat conducting part and the firstend of the electrical connecting part to the outside.
 14. Thefabrication method according to claim 9, further comprising a step of:(g) curing the molding material and taking out a cured resultantstructure before or after the cutting step (f).
 15. The fabricationmethod according to claim 9, further comprising a step of: bending aportion of the electrical connecting part that is extended to theoutside after the resultant structure taking out step (g).
 16. Afabrication method of a light emitting diode housing, comprising stepsof: (a) preparing a plurality of heat conducting parts each having achip mounting area, a heat connecting area opposed to the chip mountingarea and a neck formed between the chip mounting area and the heatconnecting area; (b) machining a sheet metal into a frame array sheethaving a circumference area with holes and a plurality of frame areassurrounded by the circumference area, wherein each of the frame areashas a circumference part and a pair of fixing parts, and at least oneelectrical connecting part each having a first end extended from thecircumference part toward the center of the frame; (c) assembling theheat conducting parts to the frame array sheet to produce a plurality ofheat conducting part-frame assemblies, wherein the first ends of thefixing parts engage with the neck of the heat conducting part and afirst end of the electrical connecting part is placed adjacent to thechip mounting area; (d) mounting the heat conducting part-frameassemblies in molds; (e) injecting molding material into the molds toform a plurality of housing body each of which integrally holds the heatconducting part, the fixing parts and the electrical connecting partwhile isolating the electrical connecting part from the heat conductingpart; and (f) cutting the fixing parts and the electrical connectingpart from the frame area sheet.
 17. The fabrication method according toclaim 16, wherein the sheet metal machining step (b) comprises punchingthe sheet metal.
 18. The fabrication method according to claim 16,wherein the heat conducting parts assembling step (c) comprises pushingeach of the heat conducting parts with the chip mounting area firstbetween the opposed first ends of the fixing parts so that the firstends hold the neck of the heat conducting part.
 19. The fabricationmethod according to claim 16, wherein the heat conducting part-frameassembly mounting step (d) comprises inserting a guide pin of the moldinto the hole of the frame array sheet to guide the mold.
 20. Thefabrication method according to claim 16, wherein the molding materialinjecting step (e) is so carried out to expose the chip mounting area ofeach of the heat conducting parts and the first end of each of theelectrical connecting parts to the outside.
 21. The fabrication methodaccording to claim 16, further comprising a step of: (g) curing themolding material and taking out a cured resultant structure before orafter the cutting step (f).
 22. The fabrication method according toclaim 16, further comprising a step of: bending a portion of each of theelectrical connecting parts that is extended to the outside after theresultant structure taking out step (g).